#include "bitcount.h"
#include "evaluate.h"
+#include "material.h"
+#include "pawns.h"
#include "thread.h"
#include "ucioption.h"
-using namespace Eval;
-
namespace {
+ // Struct EvalInfo contains various information computed and collected
+ // by the evaluation functions.
+ struct EvalInfo {
+
+ // Pointers to material and pawn hash table entries
+ Material::Entry* mi;
+ Pawns::Entry* pi;
+
+ // attackedBy[color][piece type] is a bitboard representing all squares
+ // attacked by a given color and piece type, attackedBy[color][ALL_PIECES]
+ // contains all squares attacked by the given color.
+ Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
+
+ // kingRing[color] is the zone around the king which is considered
+ // by the king safety evaluation. This consists of the squares directly
+ // adjacent to the king, and the three (or two, for a king on an edge file)
+ // squares two ranks in front of the king. For instance, if black's king
+ // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
+ // f7, g7, h7, f6, g6 and h6.
+ Bitboard kingRing[COLOR_NB];
+
+ // kingAttackersCount[color] is the number of pieces of the given color
+ // which attack a square in the kingRing of the enemy king.
+ int kingAttackersCount[COLOR_NB];
+
+ // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
+ // given color which attack a square in the kingRing of the enemy king. The
+ // weights of the individual piece types are given by the variables
+ // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
+ // KnightAttackWeight in evaluate.cpp
+ int kingAttackersWeight[COLOR_NB];
+
+ // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
+ // directly adjacent to the king of the given color. Pieces which attack
+ // more than one square are counted multiple times. For instance, if black's
+ // king is on g8 and there's a white knight on g5, this knight adds
+ // 2 to kingAdjacentZoneAttacksCount[BLACK].
+ int kingAdjacentZoneAttacksCount[COLOR_NB];
+ };
+
// Evaluation grain size, must be a power of 2
const int GrainSize = 8;
#undef S
- const Score BishopPinBonus = make_score(66, 11);
-
- // Bonus for having the side to move (modified by Joona Kiiski)
const Score Tempo = make_score(24, 11);
- // Rooks and queens on the 7th rank
- const Score RookOn7thBonus = make_score(11, 20);
- const Score QueenOn7thBonus = make_score( 3, 8);
-
- // Rooks and queens attacking pawns on the same rank
- const Score RookOnPawnBonus = make_score(10, 28);
- const Score QueenOnPawnBonus = make_score( 4, 20);
-
- // Rooks on open files (modified by Joona Kiiski)
- const Score RookOpenFileBonus = make_score(43, 21);
- const Score RookHalfOpenFileBonus = make_score(19, 10);
-
- // Penalty for rooks trapped inside a friendly king which has lost the
- // right to castle.
- const Value TrappedRookPenalty = Value(180);
-
- // Penalty for bishop with pawns on the same coloured squares
- const Score BishopPawnsPenalty = make_score(8, 12);
+ const Score BishopPinBonus = make_score(66, 11);
+ const Score RookOn7thBonus = make_score(11, 20);
+ const Score QueenOn7thBonus = make_score( 3, 8);
+ const Score RookOnPawnBonus = make_score(10, 28);
+ const Score QueenOnPawnBonus = make_score( 4, 20);
+ const Score RookOpenFileBonus = make_score(43, 21);
+ const Score RookHalfOpenFileBonus = make_score(19, 10);
+ const Score BishopPawnsPenalty = make_score(8, 12);
+ const Score UndefendedMinorPenalty = make_score(25, 10);
+ const Score TrappedRookPenalty = make_score(90, 0);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
// happen in Chess960 games.
- const Score TrappedBishopA1H1Penalty = make_score(100, 100);
-
- // Penalty for an undefended bishop or knight
- const Score UndefendedMinorPenalty = make_score(25, 10);
+ const Score TrappedBishopA1H1Penalty = make_score(50, 50);
// The SpaceMask[Color] contains the area of the board which is considered
// by the space evaluation. In the middle game, each side is given a bonus
// Function prototypes
template<bool Trace>
- Value do_evaluate(const Position& pos, Value& margin, Info& ei);
+ Value do_evaluate(const Position& pos, Value& margin);
template<Color Us>
- void init_eval_info(const Position& pos, Info& ei);
+ void init_eval_info(const Position& pos, EvalInfo& ei);
template<Color Us, bool Trace>
- Score evaluate_pieces_of_color(const Position& pos, Info& ei, Score& mobility);
+ Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
template<Color Us, bool Trace>
- Score evaluate_king(const Position& pos, Info& ei, Value margins[]);
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
template<Color Us>
- Score evaluate_threats(const Position& pos, Info& ei);
+ Score evaluate_threats(const Position& pos, EvalInfo& ei);
template<Color Us>
- int evaluate_space(const Position& pos, Info& ei);
+ int evaluate_space(const Position& pos, EvalInfo& ei);
template<Color Us>
- Score evaluate_passed_pawns(const Position& pos, Info& ei);
+ Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
- Score evaluate_unstoppable_pawns(const Position& pos, Info& ei);
+ Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
/// values, an endgame score and a middle game score, and interpolates
/// between them based on the remaining material.
- Value evaluate(const Position& pos, Value& margin, Info* ei) {
- return do_evaluate<false>(pos, margin, *ei);
+ Value evaluate(const Position& pos, Value& margin) {
+ return do_evaluate<false>(pos, margin);
}
Value margin;
std::string totals;
- Info ei;
Search::RootColor = pos.side_to_move();
TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
memset(TracedScores, 0, 2 * 16 * sizeof(Score));
- do_evaluate<true>(pos, margin, ei);
+ do_evaluate<true>(pos, margin);
totals = TraceStream.str();
TraceStream.str("");
namespace {
template<bool Trace>
-Value do_evaluate(const Position& pos, Value& margin, Info& ei) {
+Value do_evaluate(const Position& pos, Value& margin) {
assert(!pos.checkers());
+ EvalInfo ei;
Value margins[COLOR_NB];
Score score, mobilityWhite, mobilityBlack;
Thread* th = pos.this_thread();
// pawn attacks. To be done at the beginning of the evaluation.
template<Color Us>
- void init_eval_info(const Position& pos, Info& ei) {
+ void init_eval_info(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// evaluate_outposts() evaluates bishop and knight outposts squares
template<PieceType Piece, Color Us>
- Score evaluate_outposts(const Position& pos, Info& ei, Square s) {
+ Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
template<PieceType Piece, Color Us, bool Trace>
- Score evaluate_pieces(const Position& pos, Info& ei, Score& mobility, Bitboard mobilityArea) {
+ Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
Bitboard b;
- Square s, ksq;
- int mob;
- File f;
+ Square s;
Score score = SCORE_ZERO;
const Color Them = (Us == WHITE ? BLACK : WHITE);
while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
- if (Piece == KNIGHT || Piece == QUEEN)
- b = pos.attacks_from<Piece>(s);
- else if (Piece == BISHOP)
- b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN));
- else if (Piece == ROOK)
- b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN));
- else
- assert(false);
+ b = Piece == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN))
+ : Piece == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN))
+ : pos.attacks_from<Piece>(s);
ei.attackedBy[Us][Piece] |= b;
ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
}
- mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
- : popcount<Full >(b & mobilityArea));
-
+ int mob = popcount<Piece == QUEEN ? Full : Max15>(b & mobilityArea);
mobility += MobilityBonus[Piece][mob];
// Decrease score if we are attacked by an enemy pawn. Remaining part
if (ei.attackedBy[Them][PAWN] & s)
score -= ThreatenedByPawnPenalty[Piece];
- // Otherwise give a bonus if we are a bishop and can pin a piece or
- // can give a discovered check through an x-ray attack.
+ // Otherwise give a bonus if we are a bishop and can pin a piece or can
+ // give a discovered check through an x-ray attack.
else if ( Piece == BISHOP
&& (PseudoAttacks[Piece][pos.king_square(Them)] & s)
&& !more_than_one(BetweenBB[s][pos.king_square(Them)] & pos.pieces()))
&& !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
score += evaluate_outposts<Piece, Us>(pos, ei, s);
- if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5)
+ if ( (Piece == ROOK || Piece == QUEEN)
+ && relative_rank(Us, s) >= RANK_5)
{
- // Major piece on 7th rank
+ // Major piece on 7th rank and enemy king trapped on 8th
if ( relative_rank(Us, s) == RANK_7
&& relative_rank(Us, pos.king_square(Them)) == RANK_8)
- score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+ score += Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus;
- // Major piece attacking pawns on the same rank
+ // Major piece attacking enemy pawns on the same rank
Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s);
if (pawns)
- score += (Piece == ROOK ? RookOnPawnBonus
- : QueenOnPawnBonus) * popcount<Max15>(pawns);
- }
-
- // Special extra evaluation for bishops
- if (Piece == BISHOP && pos.is_chess960())
- {
- // An important Chess960 pattern: A cornered bishop blocked by
- // a friendly pawn diagonally in front of it is a very serious
- // problem, especially when that pawn is also blocked.
- if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
- {
- Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
- if (pos.piece_on(s + d) == make_piece(Us, PAWN))
- {
- if (!pos.is_empty(s + d + pawn_push(Us)))
- score -= 2*TrappedBishopA1H1Penalty;
- else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
- score -= TrappedBishopA1H1Penalty;
- else
- score -= TrappedBishopA1H1Penalty / 2;
- }
- }
+ score += popcount<Max15>(pawns) * (Piece == ROOK ? RookOnPawnBonus : QueenOnPawnBonus);
}
// Special extra evaluation for rooks
if (Piece == ROOK)
{
- // Open and half-open files
- f = file_of(s);
- if (ei.pi->file_is_half_open(Us, f))
- {
- if (ei.pi->file_is_half_open(Them, f))
- score += RookOpenFileBonus;
- else
- score += RookHalfOpenFileBonus;
- }
+ // Give a bonus for a rook on a open or half-open file
+ if (ei.pi->half_open(Us, file_of(s)))
+ score += ei.pi->half_open(Them, file_of(s)) ? RookOpenFileBonus
+ : RookHalfOpenFileBonus;
+ if (mob > 6 || ei.pi->half_open(Us, file_of(s)))
+ continue;
+
+ Square ksq = pos.king_square(Us);
// Penalize rooks which are trapped inside a king. Penalize more if
// king has lost right to castle.
- if (mob > 6 || ei.pi->file_is_half_open(Us, f))
- continue;
-
- ksq = pos.king_square(Us);
+ if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
+ && rank_of(ksq) == rank_of(s)
+ && relative_rank(Us, ksq) == RANK_1
+ && !ei.pi->half_open_on_side(Us, file_of(ksq), file_of(ksq) < FILE_E))
+ score -= (TrappedRookPenalty - make_score(mob * 8, 0)) * (pos.can_castle(Us) ? 1 : 2);
+ }
- if ( file_of(ksq) >= FILE_E
- && file_of(s) > file_of(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
- {
- // Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_right(Us, file_of(ksq)))
- score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
- else if ( file_of(ksq) <= FILE_D
- && file_of(s) < file_of(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
- {
- // Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_left(Us, file_of(ksq)))
- score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
+ // An important Chess960 pattern: A cornered bishop blocked by a friendly
+ // pawn diagonally in front of it is a very serious problem, especially
+ // when that pawn is also blocked.
+ if ( Piece == BISHOP
+ && pos.is_chess960()
+ && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
+ {
+ const enum Piece P = make_piece(Us, PAWN);
+ Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
+ if (pos.piece_on(s + d) == P)
+ score -= !pos.is_empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1Penalty * 4
+ : pos.piece_on(s + d + d) == P ? TrappedBishopA1H1Penalty * 2
+ : TrappedBishopA1H1Penalty;
}
}
// and the type of attacked one.
template<Color Us>
- Score evaluate_threats(const Position& pos, Info& ei) {
+ Score evaluate_threats(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Score score = SCORE_ZERO;
// Undefended minors get penalized even if not under attack
- undefendedMinors = pos.pieces(Them)
- & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
+ undefendedMinors = pos.pieces(Them, BISHOP, KNIGHT)
& ~ei.attackedBy[Them][ALL_PIECES];
if (undefendedMinors)
// pieces of a given color.
template<Color Us, bool Trace>
- Score evaluate_pieces_of_color(const Position& pos, Info& ei, Score& mobility) {
+ Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Score score = mobility = SCORE_ZERO;
// Do not include in mobility squares protected by enemy pawns or occupied by our pieces
- const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us));
+ const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us, PAWN, KING));
score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
// evaluate_king<>() assigns bonuses and penalties to a king of a given color
template<Color Us, bool Trace>
- Score evaluate_king(const Position& pos, Info& ei, Value margins[]) {
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// evaluate_passed_pawns<>() evaluates the passed pawns of the given color
template<Color Us>
- Score evaluate_passed_pawns(const Position& pos, Info& ei) {
+ Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
else
unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
- // If there aren't enemy attacks or pieces along the path to queen give
- // huge bonus. Even bigger if we protect the pawn's path.
- if (!unsafeSquares)
- ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
- else
- // OK, there are enemy attacks or pieces (but not pawns). Are those
- // squares which are attacked by the enemy also attacked by us ?
- // If yes, big bonus (but smaller than when there are no enemy attacks),
- // if no, somewhat smaller bonus.
- ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
+ // If there aren't enemy attacks huge bonus, a bit smaller if at
+ // least block square is not attacked, otherwise smallest bonus.
+ int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 3;
+
+ // Big bonus if the path to queen is fully defended, a bit less
+ // if at least block square is defended.
+ if (defendedSquares == squaresToQueen)
+ k += 6;
+
+ else if (defendedSquares & blockSq)
+ k += (unsafeSquares & defendedSquares) == unsafeSquares ? 4 : 2;
+
+ mbonus += Value(k * rr), ebonus += Value(k * rr);
}
} // rr != 0
// evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
// conservative and returns a winning score only when we are very sure that the pawn is winning.
- Score evaluate_unstoppable_pawns(const Position& pos, Info& ei) {
+ Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
Bitboard b, b2, blockers, supporters, queeningPath, candidates;
Square s, blockSq, queeningSquare;
// twice. Finally, the space bonus is scaled by a weight taken from the
// material hash table. The aim is to improve play on game opening.
template<Color Us>
- int evaluate_space(const Position& pos, Info& ei) {
+ int evaluate_space(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
projects / stockfish / blobdiff